1. Field
One or more embodiments of the present disclosure relate to a composite anode active material, an anode including the composite anode active material, a lithium battery including the anode, and a method of preparing the composite anode active material.
2. Description of the Related Technology
Lithium batteries have high voltage and high energy density, and thus are used in various applications. Lithium batteries for devices such as electric vehicles should be operable at high temperatures, be able to charge or discharge a large amount of electricity, and have long-term usability. Thus, lithium batteries for such devices should have high-discharge capacity and a long lifetime.
Carbonaceous materials are porous and stable with little volumetric change during charging and discharging. However, carbonaceous materials may lead to a low-battery capacity due to the porous structure of carbon. For example, graphite in the form of LiC6 has a theoretical capacity density of about 372 mAh/g. Additionally, carbonaceous materials may have unsatisfactory high-rate characteristics.
Metals that are alloyable with lithium may be used as an anode active material with a higher electrical capacity as compared with carbonaceous materials. Examples of metals that are alloyable with lithium are silicon (Si), tin (Sn), aluminum (Al), and the like. However, these metals have low charge/discharge efficiency, easily deteriorate, and have relatively poor lifetime characteristics. For example, degradation may occur with repeated charging and discharging of metals such as tin. The tin may be in the form of particles where agglomeration and breakage of tin particles may occur, leading to electric shorts.
Therefore, there is a demand for a lithium battery with improved charge/discharge efficiency, discharge capacity and lifetime characteristics.